The absorption, excitation and emission spectra of methotrexate (MTX) solutions in natural saline water and sodium hydroxide at 10(-4)-10(-5) MpH=8.4 were measured, while they were exposed to coherent and uncoherent visible and near ultraviolet (UV) light. Xe and Hg lamp and also a nitrogen pulsed laser radiation were used. The absorption spectra exhibited spectral bands between 225 nm and 450 ...

To understand the optical properties of atoms in solid state matrices, the absorption, excitation, and emission spectra of rubidium doped thin-films of argon, krypton, and xenon were investigated in detail. A two-dimensional spectral analysis extends earlier reports on the excitation and emission properties of rubidium in rare-gas hosts. We found that the doped crystals of krypton and xenon exh...

Excitation–emission matrix (EEM) fluorescence spectroscopy was employed to study the chemical nature of organic matter readily released into solution from sediment particles during episodes of resuspension. Surface sediment samples collected from five locations within the Hudson River Estuary and the Inner New York Bight were resuspended in their respective bottom waters for periods ranging fro...

The direction of excitation energy migration is reversed in a system composed of {Ru(bpy)(2)}-{pyridylporphyrin}(2) by the addition of a Zn(2+) ion. The Zn(2+) system shows an excitation-wavelength dependent emission.

Fluorescence imaging has been demonstrated to be able to detect and diagnose different tumour types in a range of biological tissues including cervix, lung, and along the gastrointestinal tract. An approach based on laser induced tissue autofluorescence may be applied minimally invasively using endoscopes, although there is a high degree of overlap in endogenous fluorophore excitation/emission ...

Cathodoluminescence (CL) spectra from silicon doped and undoped wurtzite n-type GaN have been measured in a SEM under a wide range of electron beam excitation conditions, which include accelerating voltage, beam current, magnification, beam diameter, and specimen temperature. The CL intensity dependence on excitation density was analyzed using a power-law model (I CL proportional, variant J m )...

BACKGROUND AND OBJECTIVE The hamster cheek pouch carcinogenesis model, using chronic treatments of dimethylbenz[alpha]anthracene (DMBA) was used as a model system to investigate changes in epithelial tissue autofluorescence throughout the dysplasia-carcinoma sequence. STUDY DESIGN/MATERIALS AND METHODS Fluorescence emission spectra were measured weekly from 42 DMBA-treated animals and 20 cont...

The development of single-molecule fluorescence energy transfer (FRET) microscopy has provided ground-breaking insights to many biological systems. While the acquisition and pre-data processing side of the technique have been much improved since, the data analysis for determining transition rates between states often still relies on simple and arbitrary methods such as applying thresholds and i...

The prompt neutron and γ emission from primary fission fragments are calculated for thermal neutron induced fission of 235U and 239Pu and for spontaneous fission of 252Cf using a Monte Carlo Hauser-Feshbach approach for the evaporation of the excited fission fragments. Remaining free model parameters, such as excitation energy sharing and initial spin distribution, are determined by comparison ...

The application of generalized rank annihilation method (GRAM) to the analysis of fluorescence excitation-emission matrices of mixtures of piroxicam and pyridoxine is described. The input of GRAM consists of two bilinear data matrices, i.e. one for unknown and one for the calibration sample. The excitation wavelength range was from 290 to 340 nm and the emission was recorded from 370 to 560 nm....